LOL! This could be your lucrative retirement job.
Maybe, my guess is smart people and i stress that point will come up with a method that will make it fast, possibly at first it will be the foundation, that needs time to fully cure first, usually 3 weeks. The foundation obviously needs to be deep for special reasons.
And i doubt it will be a simple wall like Israel has in the urban areas like at the Ca border, there it has to be artistic and functional. Not just miles of vertical H steel beams with pre stressed panels between them.